V3c video component track alternatives

ABSTRACT

An apparatus includes a communication interface and a processor operably coupled to the communication interface. The communication interface receives a plurality of tracks in a compressed bitstream. The processor identifies an atlas track corresponding to a point cloud compression (PCC) component and identifies a set of first component tracks that is referenced by the atlas track and at least one second component track, each of the at least one second component track is an alternative version of a first component track of the set of first component tracks. The processor also determines which of the set of first component tracks and the at least one second component track are appropriate versions of the PCC component. The processor further decodes the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track.

CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM

This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Patent Application No. 63/134,006 filed on Jan. 5, 2021,U.S. Provisional Patent Application No. 63/136,265 filed on Jan. 12,2021, U.S. Provisional Patent Application No. 63/171,369 filed on Apr.6, 2021, U.S. Provisional Patent Application No. 63/179,744 filed onApr. 26, 2021 and U.S. Provisional Patent Application No. 63/181,056filed on Apr. 28, 2021, which are hereby incorporated by reference inits entirety.

TECHNICAL FIELD

This disclosure relates generally to video processing devices andprocesses. More specifically, this disclosure relates to visualvolumetric video-based coding (V3C) video component track alternatives.

BACKGROUND

ISO/IEC 23090-10 carriage of visual volumetric video-based coding (V3C)data supports alternative representation of V3C video component tracks.However, the use of such features with the combination with a V3C atlastile track is not fully provided.

SUMMARY

This disclosure provides V3C video component track alternatives.

In a first embodiment, a decoding device includes a communicationinterface and a processor operably coupled to the communicationinterface. The communication interface is configured to receive aplurality of tracks in a compressed bitstream. The processor isconfigured to identify an atlas track corresponding to a point cloudcompression (PCC) component and identify a set of first component tracksthat is referenced by the atlas track and at least one second componenttrack, each of the at least one second component track is an alternativeversion of a first component track of the set of first component tracks.The processor is also configured to determine which of the set of firstcomponent tracks and the at least one second component track areappropriate versions of the PCC component. The processor is furtherconfigured to decode the appropriate version of the PCC component fromamong the set of first component tracks and the at least one secondcomponent track.

In a second embodiment, a decoding device includes a communicationinterface and a processor operably coupled to the communicationinterface. The communication interface is configured to receive adynamic adaptive streaming over HTTP (DASH) media presentationdescription (MPD) about a point cloud compression (PCC) data and aplurality of tracks in a compressed bitstream. The processor isconfigured to, based on information in the DASH MPD, identify a firstatlas bitstream and a second atlas bitstream that is an alternativeversion of the first atlas bitstream based on the first atlas bitstreamand the second atlas bitstream having a same value of an atlas ID. Theprocessor is also configured to determine which of a first atlas trackand a second atlas track is an appropriate version of the PCC data. Theprocessor is further configured to decode the appropriate version of thePCC data.

In a third embodiment, a method includes receiving a plurality of tracksin a compressed bitstream. The method also includes identifying an atlastrack corresponding to a point cloud compression (PCC) component andidentifying a set of first component tracks that is referenced by theatlas track and at least one second component track, each of the atleast one second component track is an alternative version of a firstcomponent track of the set of first component tracks. The method furtherincludes determining which of the set of first component tracks and theat least one second component track are appropriate versions of the PCCcomponent. In addition, the method includes decoding the appropriateversion of the PCC component from among the set of first componenttracks and the at least one second component track.

In a fourth embodiment, an encoder device includes a processor and acommunication interface operably coupled to the processor. The processoris configured to encode an atlas track corresponding to a point cloudcompression (PCC) component. The processor is also configured to encodethe PCC component in a first component track that references the atlastrack. The processor is further configured to encode an alternativeversion of the PCC component from the first component track in a secondcomponent track. The communication interface is configured to transmit acompressed bitstream including the atlas track, the first componenttrack, and the second component track.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system, or partthereof that controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example communication system in accordance with anembodiment of this disclosure;

FIGS. 2 and 3 illustrate example electronic devices in accordance withan embodiment of this disclosure;

FIG. 4 illustrates a block diagram of an exampleenvironment-architecture in accordance with an embodiment of thisdisclosure;

FIGS. 5A-5C illustrates an example files in accordance with thisdisclosure; and

FIG. 6 illustrates an example method for V3C video component trackalternatives according to this disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 6, described below, and the various embodiments used todescribe the principles of the present disclosure are by way ofillustration only and should not be construed in any way to limit thescope of the disclosure. Those skilled in the art will understand thatthe principles of the present disclosure may be implemented in any typeof suitably arranged device or system.

Alternative content representation is defined in ISO/IEC 23090-10Carriage of Video-based Point Cloud Compression Data in a very highlevel. 1.1.1.1 V3C content alternatives provide that V3C content may beencoded as different versions in the file format. Different alternativesare indicated by the alternative tracks mechanism defined in ISO/IEC14496-12 (i.e., altenate_group field of the TrackHeaderBox). V3C atlastracks which have the same alternate_group value shall be differentversions of the same V3C content.

1.1.1.2 V3C video component alternatives provides that V3C videocomponent tracks may have alternatives. In such a case, only ne of theV3C video component tracks that belong to an alternative group shall bereferenced by the V3C atlas track or V3C atlas tile track. V3C videocomponent tracks which are alternatives of each other should use thealternate grouping mechanism, as defined in ISO/IEC 14496-12.

As a single content of V-PCC is composed of many components andcombination of components that can widely vary. A detailed descriptionabout complicated or complex cases needs further defining. When a V3Ccontent has alternatives, a sample entry of a track belongs to all V3Ccontents in an alternative relationship that may not provide enoughinformation to show the differences between alternative versions. Theapplication may use additional external mechanisms, e.g., dynamicadaptive streaming over HTTP (DASH) media presentation description(MPD), scene descriptions, etc., to get information to select oneappropriate version for display.

FIG. 1 illustrates an example communication system 100 in accordancewith an embodiment of this disclosure. The embodiment of thecommunication system 100 shown in FIG. 1 is for illustration only. Otherembodiments of the communication system 100 can be used withoutdeparting from the scope of this disclosure.

The communication system 100 includes a network 102 that facilitatescommunication between various components in the communication system100. For example, the network 102 can communicate IP packets, framerelay frames, Asynchronous Transfer Mode (ATM) cells, or otherinformation between network addresses. The network 102 includes one ormore local area networks (LANs), metropolitan area networks (MANs), widearea networks (WANs), all or a portion of a global network such as theInternet, or any other communication system or systems at one or morelocations.

In this example, the network 102 facilitates communications between aserver 104 and various client devices 106-116. The client devices106-116 may be, for example, a smartphone, a tablet computer, a laptop,a personal computer, a wearable device, a HMD, or the like. The server104 can represent one or more servers. Each server 104 includes anysuitable computing or processing device that can provide computingservices for one or more client devices, such as the client devices106-116. Each server 104 could, for example, include one or moreprocessing devices, one or more memories storing instructions and data,and one or more network interfaces facilitating communication over thenetwork 102. As described in more detail below, the server 104 cantransmit a compressed bitstream, representing a point cloud, to one ormore display devices, such as a client device 106-116. In certainembodiments, each server 104 can include an encoder.

Each client device 106-116 represents any suitable computing orprocessing device that interacts with at least one server (such as theserver 104) or other computing device(s) over the network 102. Theclient devices 106-116 include a desktop computer 106, a mobiletelephone or mobile device 108 (such as a smartphone), a PDA 110, alaptop computer 112, a tablet computer 114, and an HMD 116. However, anyother or additional client devices could be used in the communicationsystem 100. Smartphones represent a class of mobile devices 108 that arehandheld devices with mobile operating systems and integrated mobilebroadband cellular network connections for voice, short message service(SMS), and Internet data communications. The HMD 116 can display a 360°scene including one or more 3D point clouds. In certain embodiments, anyof the client devices 106-116 can include an encoder, decoder, or both.For example, the mobile device 108 can record a video and then encodethe video enabling the video to be transmitted to one of the clientdevices 106-116. In another example, the laptop computer 112 can be usedto generate a virtual 3D point cloud, which is then encoded andtransmitted to one of the client devices 106-116.

In this example, some client devices 108-116 communicate indirectly withthe network 102. For example, the mobile device 108 and PDA 110communicate via one or more base stations 118, such as cellular basestations or eNodeBs (eNBs). Also, the laptop computer 112, the tabletcomputer 114, and the HMD 116 communicate via one or more wirelessaccess points 120, such as IEEE 802.11 wireless access points. Note thatthese are for illustration only and that each client device 106-116could communicate directly with the network 102 or indirectly with thenetwork 102 via any suitable intermediate device(s) or network(s). Incertain embodiments, the server 104 or any client device 106-116 can beused to compress a point cloud, generate a bitstream that represents thepoint cloud, and transmit the bitstream to another client device such asany client device 106-116.

In certain embodiments, any of the client devices 106-114 transmitinformation securely and efficiently to another device, such as, forexample, the server 104. Also, any of the client devices 106-116 cantrigger the information transmission between itself and the server 104.Any of the client devices 106-114 can function as a VR display whenattached to a headset via brackets, and function similar to HMD 116. Forexample, the mobile device 108 when attached to a bracket system andworn over the eyes of a user can function similarly as the HMD 116. Themobile device 108 (or any other client device 106-116) can trigger theinformation transmission between itself and the server 104.

In certain embodiments, any of the client devices 106-116 or the server104 can create a 3D point cloud, compress a 3D point cloud, transmit a3D point cloud, receive a 3D point cloud, render a 3D point cloud, or acombination thereof. For example, the server 104 can then compress 3Dpoint cloud to generate a bitstream and then transmit the bitstream toone or more of the client devices 106-116. For another example, one ofthe client devices 106-116 can compress a 3D point cloud to generate abitstream and then transmit the bitstream to another one of the clientdevices 106-116 or to the server 104.

Although FIG. 1 illustrates one example of a communication system 100,various changes can be made to FIG. 1. For example, the communicationsystem 100 could include any number of each component in any suitablearrangement. In general, computing and communication systems come in awide variety of configurations, and FIG. 1 does not limit the scope ofthis disclosure to any particular configuration. While FIG. 1illustrates one operational environment in which various featuresdisclosed in this patent document can be used, these features could beused in any other suitable system.

FIGS. 2 and 3 illustrate example electronic devices in accordance withan embodiment of this disclosure. In particular, FIG. 2 illustrates anexample server 200, and the server 200 could represent the server 104 inFIG. 1. The server 200 can represent one or more encoders, decoders,local servers, remote servers, clustered computers, and components thatact as a single pool of seamless resources, a cloud-based server, andthe like. The server 200 can be accessed by one or more of the clientdevices 106-116 of FIG. 1 or another server.

As shown in FIG. 2, the server 200 includes a bus system 205 thatsupports communication between at least one processing device (such as aprocessor 210), at least one storage device 215, at least onecommunications interface 220, and at least one input/output (I/O) unit225. The server 200 can represent one or more local servers, one or morecompression servers, or one or more encoding servers, such as anencoder. In certain embodiments, the encoder can perform decoding.

The processor 210 executes instructions that can be stored in a memory230. The processor 210 can include any suitable number(s) and type(s) ofprocessors or other devices in any suitable arrangement. Example typesof processors 210 include microprocessors, microcontrollers, digitalsignal processors, field programmable gate arrays, application specificintegrated circuits, and discrete circuitry. In certain embodiments, theprocessor 210 can encode a 3D point cloud stored within the storagedevices 215. In certain embodiments, encoding a 3D point cloud alsodecodes the 3D point cloud to ensure that when the point cloud isreconstructed, the reconstructed 3D point cloud matches the 3D pointcloud prior to the encoding.

The memory 230 and a persistent storage 235 are examples of storagedevices 215 that represent any structure(s) capable of storing andfacilitating retrieval of information (such as data, program code, orother suitable information on a temporary or permanent basis). Thememory 230 can represent a random-access memory or any other suitablevolatile or non-volatile storage device(s). For example, theinstructions stored in the memory 230 can include instructions forencode an atlas track corresponding to a PCC component, instructions forencoding the PCC component in a first component track that referencesthe atlas tracks, instructions for encoding an alternative version ofthe PCC component from the first component track in a second componenttrack, as well as instructions for transmitting a compressed bitstreamincluding the atlas track, the first component track, and the secondcomponent track.

The instructions stored in the memory 230 can also include instructionsfor receiving a plurality of tracks in a compressed bitstream,instructions for identifying an atlas track corresponding to a PCCcomponent, instructions for identifying a set of first component tracksthat is referenced by the atlas track and at least one second componenttrack, instructions for determining which of the set of first componenttracks and the at least one second component track are appropriateversions of the PCC component; and instructions for decoding theappropriate version of the PCC component from among the set of firstcomponent tracks and the at least one second component tracks. Theinstructions stored in the memory 230 can also include instructions forrendering a 360° scene, as viewed through a VR headset, such as HMD 116of FIG. 1. The persistent storage 235 can contain one or more componentsor devices supporting longer-term storage of data, such as a read onlymemory, hard drive, Flash memory, or optical disc.

The communications interface 220 supports communications with othersystems or devices. For example, the communications interface 220 couldinclude a network interface card or a wireless transceiver facilitatingcommunications over the network 102 of FIG. 1. The communicationsinterface 220 can support communications through any suitable physicalor wireless communication link(s). For example, the communicationsinterface 220 can transmit a bitstream containing a 3D point cloud toanother device such as one of the client devices 106-116.

The I/O unit 225 allows for input and output of data. For example, theI/O unit 225 can provide a connection for user input through a keyboard,mouse, keypad, touchscreen, or other suitable input device. The I/O unit225 can also send output to a display, printer, or other suitable outputdevice. Note, however, that the I/O unit 225 can be omitted, such aswhen I/O interactions with the server 200 occur via a networkconnection.

Note that while FIG. 2 is described as representing the server 104 ofFIG. 1, the same or similar structure could be used in one or more ofthe various client devices 106-116. For example, a desktop computer 106or a laptop computer 112 could have the same or similar structure asthat shown in FIG. 2.

FIG. 3 illustrates an example electronic device 300, and the electronicdevice 300 could represent one or more of the client devices 106-116 inFIG. 1. The electronic device 300 can be a mobile communication device,such as, for example, a mobile station, a subscriber station, a wirelessterminal, a desktop computer (similar to the desktop computer 106 ofFIG. 1), a portable electronic device (similar to the mobile device 108,the PDA 110, the laptop computer 112, the tablet computer 114, or theHMD 116 of FIG. 1), and the like. In certain embodiments, one or more ofthe client devices 106-116 of FIG. 1 can include the same or similarconfiguration as the electronic device 300. In certain embodiments, theelectronic device 300 is an encoder, a decoder, or both. For example,the electronic device 300 is usable with data transfer, image or videocompression, image or video decompression, encoding, decoding, and mediarendering applications.

As shown in FIG. 3, the electronic device 300 includes an antenna 305, aradio-frequency (RF) transceiver 310, transmit (TX) processing circuitry315, a microphone 320, and receive (RX) processing circuitry 325. The RFtransceiver 310 can include, for example, a RF transceiver, a BLUETOOTHtransceiver, a WI-FI transceiver, a ZIGBEE transceiver, an infraredtransceiver, and various other wireless communication signals. Theelectronic device 300 also includes a speaker 330, a processor 340, aninput/output (I/O) interface (IF) 345, an input 350, a display 355, amemory 360, and a sensor(s) 365. The memory 360 includes an operatingsystem (OS) 361, and one or more applications 362.

The RF transceiver 310 receives, from the antenna 305, an incoming RFsignal transmitted from an access point (such as a base station, WI-FIrouter, or BLUETOOTH device) or other device of the network 102 (such asa WI-FI, BLUETOOTH, cellular, 5G, LTE, LTE-A, WiMAX, or any other typeof wireless network). The RF transceiver 310 down-converts the incomingRF signal to generate an intermediate frequency or baseband signal. Theintermediate frequency or baseband signal is sent to the RX processingcircuitry 325 that generates a processed baseband signal by filtering,decoding, and/or digitizing the baseband or intermediate frequencysignal. The RX processing circuitry 325 transmits the processed basebandsignal to the speaker 330 (such as for voice data) or to the processor340 for further processing (such as for web browsing data).

The TX processing circuitry 315 receives analog or digital voice datafrom the microphone 320 or other outgoing baseband data from theprocessor 340. The outgoing baseband data can include web data, e-mail,or interactive video game data. The TX processing circuitry 315 encodes,multiplexes, and/or digitizes the outgoing baseband data to generate aprocessed baseband or intermediate frequency signal. The RF transceiver310 receives the outgoing processed baseband or intermediate frequencysignal from the TX processing circuitry 315 and up-converts the basebandor intermediate frequency signal to an RF signal that is transmitted viathe antenna 305.

The processor 340 can include one or more processors or other processingdevices. The processor 340 can execute instructions that are stored inthe memory 360, such as the OS 361 in order to control the overalloperation of the electronic device 300. For example, the processor 340could control the reception of forward channel signals and thetransmission of reverse channel signals by the RF transceiver 310, theRX processing circuitry 325, and the TX processing circuitry 315 inaccordance with well-known principles. The processor 340 can include anysuitable number(s) and type(s) of processors or other devices in anysuitable arrangement. For example, in certain embodiments, the processor340 includes at least one microprocessor or microcontroller. Exampletypes of processor 340 include microprocessors, microcontrollers,digital signal processors, field programmable gate arrays, applicationspecific integrated circuits, and discrete circuitry.

The processor 340 is also capable of executing other processes andprograms resident in the memory 360, such as operations that receive andstore data. The processor 340 can move data into or out of the memory360 as required by an executing process. In certain embodiments, theprocessor 340 is configured to execute the one or more applications 362based on the OS 361 or in response to signals received from externalsource(s) or an operator. Example, applications 362 can include anencoder, a decoder, a VR or AR application, a camera application (forstill images and videos), a video phone call application, an emailclient, a social media client, a SMS messaging client, a virtualassistant, and the like. In certain embodiments, the processor 340 isconfigured to receive and transmit media content.

The processor 340 is also coupled to the I/O interface 345 that providesthe electronic device 300 with the ability to connect to other devices,such as client devices 106-114. The I/O interface 345 is thecommunication path between these accessories and the processor 340.

The processor 340 is also coupled to the input 350 and the display 355.The operator of the electronic device 300 can use the input 350 to enterdata or inputs into the electronic device 300. The input 350 can be akeyboard, touchscreen, mouse, track ball, voice input, or other devicecapable of acting as a user interface to allow a user in interact withthe electronic device 300. For example, the input 350 can include voicerecognition processing, thereby allowing a user to input a voicecommand. In another example, the input 350 can include a touch panel, a(digital) pen sensor, a key, or an ultrasonic input device. The touchpanel can recognize, for example, a touch input in at least one scheme,such as a capacitive scheme, a pressure sensitive scheme, an infraredscheme, or an ultrasonic scheme. The input 350 can be associated withthe sensor(s) 365 and/or a camera by providing additional input to theprocessor 340. In certain embodiments, the sensor 365 includes one ormore inertial measurement units (IMUs) (such as accelerometers,gyroscope, and magnetometer), motion sensors, optical sensors, cameras,pressure sensors, heart rate sensors, altimeter, and the like. The input350 can also include a control circuit. In the capacitive scheme, theinput 350 can recognize touch or proximity.

The display 355 can be a liquid crystal display (LCD), light-emittingdiode (LED) display, organic LED (OLED), active matrix OLED (AMOLED), orother display capable of rendering text and/or graphics, such as fromwebsites, videos, games, images, and the like. The display 355 can besized to fit within an HMD. The display 355 can be a singular displayscreen or multiple display screens capable of creating a stereoscopicdisplay. In certain embodiments, the display 355 is a heads-up display(HUD). The display 355 can display 3D objects, such as a 3D point cloud.

The memory 360 is coupled to the processor 340. Part of the memory 360could include a RAM, and another part of the memory 360 could include aFlash memory or other ROM. The memory 360 can include persistent storage(not shown) that represents any structure(s) capable of storing andfacilitating retrieval of information (such as data, program code,and/or other suitable information). The memory 360 can contain one ormore components or devices supporting longer-term storage of data, suchas a read only memory, hard drive, Flash memory, or optical disc. Thememory 360 also can contain media content. The media content can includevarious types of media such as images, videos, three-dimensionalcontent, VR content, AR content, 3D point clouds, and the like.

The electronic device 300 further includes one or more sensors 365 thatcan meter a physical quantity or detect an activation state of theelectronic device 300 and convert metered or detected information intoan electrical signal. For example, the sensor 365 can include one ormore buttons for touch input, a camera, a gesture sensor, an IMU sensors(such as a gyroscope or gyro sensor and an accelerometer), an eyetracking sensor, an air pressure sensor, a magnetic sensor ormagnetometer, a grip sensor, a proximity sensor, a color sensor, abio-physical sensor, a temperature/humidity sensor, an illuminationsensor, an Ultraviolet (UV) sensor, an Electromyography (EMG) sensor, anElectroencephalogram (EEG) sensor, an Electrocardiogram (ECG) sensor, anIR sensor, an ultrasound sensor, an iris sensor, a fingerprint sensor, acolor sensor (such as a Red Green Blue (RGB) sensor), and the like. Thesensor 365 can further include control circuits for controlling any ofthe sensors included therein.

The electronic device 300 can encode an atlas track corresponding to aPCC component. The electronic device 300 can encode the PCC component ina first component track that references the atlas track. The electronicdevice 300 can encode an alternative version of the PCC component fromthe first component track in a second component track. The electronicdevice 300 can transmit a compressed bitstream including the atlastrack, the first component track, and the second component track. Theelectronic device 300 can encode the media content to generate abitstream, such that the bitstream can be transmitted directly toanother electronic device or indirectly such as through the network 102of FIG. 1. Another electronic device, similar to the electronic device300, can receive a bitstream directly from the electronic device 300 orindirectly such as through the network 102 of FIG. 1.

Similarly, when decoding media content included in a bitstream thatrepresents a 3D point cloud, the electronic device 300 receives acompressed bitstream. In certain embodiments, the electronic device 300can identify an atlas track corresponding to a PCC component. Theelectronic device 300 can identify a set of first component tracks thatis referenced by the atlas track and at least one second componenttrack, where each of the at least one second component track is analternative version of a first component track of the set of firstcomponent tracks. The electronic device 300 can determine which of theset of first component tracks and the at least one second componenttracks are appropriate versions of the PCC component. The electronicdevice 300 can decode the appropriate version of the PCC component fromamong the set of first component tracks and the at least one secondcomponent track. In certain embodiments, after reconstructing the 3Dpoint cloud, the electronic device 300 can render the 3D point cloud inthree dimensions via the display 355.

Although FIGS. 2 and 3 illustrate examples of electronic devices,various changes can be made to FIGS. 2 and 3. For example, variouscomponents in FIGS. 2 and 3 could be combined, further subdivided, oromitted and additional components could be added according to particularneeds. As a particular example, the processor 340 could be divided intomultiple processors, such as one or more central processing units (CPUs)and one or more graphics processing units (GPUs). In addition, as withcomputing and communication, electronic devices and servers can come ina wide variety of configurations, and FIGS. 2 and 3 do not limit thisdisclosure to any particular electronic device or server.

FIG. 4 illustrates a block diagram of an exampleenvironment-architecture 400 for storage of V3C video componentalternatives in accordance with an embodiment of this disclosure. Theembodiment of FIG. 4 is for illustration only. Other embodiments can beused without departing from the scope of this disclosure.

As shown in FIG. 4, the example environment-architecture 400 includes anencoder 410 and a decoder 450 in communication over a network 402. Thenetwork 402 can be the same as or similar to the network 102 of FIG. 1.In certain embodiments, the network 402 represents a “cloud” ofcomputers interconnected by one or more networks, where the network is acomputing system utilizing clustered computers and components that actas a single pool of seamless resources when accessed. Also, in certainembodiments, the network 402 is connected with one or more servers (suchas the server 104 of FIG. 1, the server 200), one or more electronicdevices (such as the client devices 106-116 of FIG. 1, the electronicdevice 300), the encoder 410, and the decoder 450. Further, in certainembodiments, the network 402 can be connected to an informationrepository (not shown) that contains media content that can be encodedby the encoder 410, decoded by the decoder 450, or rendered anddisplayed on an electronic device.

In certain embodiments, the encoder 410 and the decoder 450 canrepresent the server 104, one of the client devices 106-116 of FIG. 1,or another suitable device. The encoder 410 and the decoder 450 caninclude internal components similar to the server 200 of FIG. 2 andelectronic device 300 of FIG. 3. In certain embodiments, the encoder 410and the decoder 450 can be a “cloud” of computers interconnected by oneor more networks, where each is a computing system utilizing clusteredcomputers and components to act as a single pool of seamless resourceswhen accessed through the network 402. In some embodiments, a portion ofthe components included in the encoder 410 or the decoder 450 can beincluded in different devices, such as multiple servers 104 or 200,multiple client devices 106-116, or other combination of differentdevices. In certain embodiments, the encoder 410 is operably connectedto an electronic device or a server while the decoder 450 is operablyconnected to an electronic device. In certain embodiments, the encoder410 and the decoder 450 are the same device or operably connected to thesame device.

The encoder 410 receives media content from another device such as aserver (similar to the server 104 of FIG. 1, the server 200 of FIG. 2)or an information repository (such as a database). The encoder 410 canencode an atlas track corresponding to a PCC component, encode the PCCcomponent in a first component track that references the atlas track,encode an alternative version of the PCC component from the firstcomponent track in a second component track, and transmit a compressedbitstreams including the atlas track, the first component track, and thesecond component track. The encoder 410 transmits frames representingthe media content as an encoded bitstream. The bitstream can betransmitted to an information repository (such as a database) or anelectronic device that includes a decoder (such as the decoder 450), orthe decoder 450 itself through the network 402.

The decoder 450 can receive a bitstream that represents media content.In certain embodiments, the decoder 450 can identify an atlas trackcorresponding to a PCC component, identify a set of first componenttracks that is referenced by the atlas track and at least one secondcomponent track, where each of the at least one second component trackis an alternative version of a first component track of the set of firstcomponent tracks, determine which of the set of first component tracksand the at least one second component tracks are appropriate versions ofthe PCC component, and decode the appropriate version of the PCCcomponent from among the set of first component tracks and the at leastone second component track.

Although FIG. 4 illustrates examples of an encoder and a decoder,various changes can be made to FIG. 4. For example, various componentsin FIG. 4 could be combined, further subdivided, or omitted andadditional components could be added according to particular needs. As aparticular example, the encoder 410 or decoder 450 could be divided intomultiple components. In addition, as with computing and communication,encoders and decoders can come in a wide variety of configurations, andFIG. 4 does not limit this disclosure to any particular encoder ordecoder.

FIGS. 5A through 5C illustrates an example files 500, 502, 504 inaccordance with this disclosure. In particular, FIG. 5A illustrates file500, FIG. 5B illustrates file 502, and FIG. 5C illustrates file 504. Theembodiments of the files 500, 502, 504 illustrated in FIGS. 5A through5C are for illustration only. FIGS. 5A through 5C do not limit the scopeof this disclosure to any particular implementation of an electronicdevice.

As shown in FIGS. 5A through 5C, the file 500 can include at atlas track506 and a plurality of component tracks 508. More than one version of acomponent can be stored in a video-based PCC (V-PCC) file 500. Decodingcan begin from at an atlas track 506 and the file 500 can include acombination of atlas tracks 506 and component tracks 508. An atlas track506 is a first track read for processing of a PCC component. Fordecoding a PCC component, an atlas track 506 and the correspondingcomponent tracks 508 associated with the atlas track 506 are decoded.The term “atlas” can be interchangeable with “patches”. A single atlastrack 506 can be used per V-PCC objects, where an atlas track 506includes a group of patches. A file 500 can include multiple atlastracks 506 when atlas tracks 506 contain totally different objects ordifferently encoded versions of an object.

Track alternatives are indicated by the alternate track mechanismdefined in ISO/IEC 14496-12 (i.e., alternate_group field of theTrackHeaderBox). V3C content can have many versions. In certainembodiments, tracks including V3C contents in alternative relationshiphave the same alternate_group value 512 in their TrackHeaderBox. Asingle V3C content may have alternative representation of V3C videocomponents. V3C video component tracks 508 that have the samealternate_group value 512 are different representations of the same V3Cvideo component.

When V3C content has alternatives, more than two V3C contents in analternative relationship are not to be played together, which means thatone of the two V3C contents does not need to be processed. All V3C videocomponent tracks 508 that include V3C contents in alternativerelationship shall be referenced by one and only one V3C atlas track orV3C atlas tile track. When V3C content have alternatives in a file 500,a sample entry of component tracks 508 belonging to the V3C content inalternative relationships may not provide enough information to show thedifferences between the alternative versions. The application may useadditional external mechanisms, e.g. DASH 1MPD, scene descriptions, andso on, to get information to select one appropriate version for play.

When a V3C video component track 508 has alternatives versions, only oneof the V3C video component tracks 508 that belong to a same alternativegroup is referenced by the V3C atlas track 506 or V3C atlas tile track520. V3C video component tracks 508 not directly referenced by the V3Catlas track 506 or V3C atlas tile track 520 are also represented asrestricted video and have a generic restricted sample entry ‘resv’ withadditional requirements. When a V3C video component track 508 hasalternatives, a sample entry of each alternative component track 508provides enough information to show the differences between thealternative representations in order to select one appropriaterepresentation for playing by the application.

FIG. 5A shows an example of a V3C content using track alternatives ofV3C video components tracks 508. A scheme type value 514 for thecomponent tracks 508 with a track ID value 516 within the range of 2 and8, ‘vvvc’ indicates they are the V3C video components tracks. Thecomponent tracks 508 with a track ID value 516 of 2, 3, and 4 are knownas the V3C video component track 508 related to the V3C atlas track 506with track ID value 516 of 1. The relationship between the componentstracks 508 related to the atlas track 506 is included in information ofthe atlas track 506 that directly lists the component track 508. Eventhough the component tracks 508 with track ID values 516 of 5, 6, 7, and8 are not directly listed, these component tracks 508 are alsoidentified as V3C video component tracks 508 related to the same V3Catlas track 506 by having same alternative group value 512 of trackalternative group information with the component tracks 508 with trackID values 516 of 2, 3, and 4. The component tracks 508 with thealternate group values 512 of 10, 11, and 12, respectively, are thealternative representations for the same components of V3C content. Theoriginal format value 518 in RestrictedSchemeInfoBox shows that thecomponent tracks 508 with a track ID value 516 of 2, 3, and 4 are AVCencoded representations and the component tracks 508 with track IDvalues 516 of 5, 6, and 7 are HEVC encoded alternative representationsof the component tracks 508 with track ID value of 2, 3 and 4,respectively. The original format value 518 in RestrictedSchemeInfoBoxshows that the component tracks 508 with a track ID value 516 of 8 is aVVC encoded alternative representation of the component tracks 508 witha track ID value 516 of 4 and 7.

As shown in FIG. 5B, file 502 includes V3C content that uses trackalternatives of V3C video components tracks 508 with V3C atlas tiletracks 520. The scheme type value 514 of the component tracks 508 withtrack ID values 516 within the range between 21 and 28 are set to‘vvvc’, which indicates the component tracks 508 are V3C videocomponents tracks. The track reference information in the V3C atlas tiletracks 520 show that the component tracks 508 with track ID values 516of 21, 22 and 23 are V3C video components tracks 508 related to V3Catlas tile track 520 with a track ID value 516 of 11 and the componenttracks 508 with track ID values 516 within the range between 24, 25 and26 are V3C video components tracks 508 related to V3C atlas tile track520 with track ID value 516 of 12. Based on the alternate group value512, the component tracks 508 with track ID values 516 of 27 and 28 areidentified as the alternative representation 522 of the component track508 with a track ID value 516 of 24 and 25, respectively, which meansthat they are also the V3C component tracks 508 related to the V3C atlastrack 506 with track ID value 516 of 12. The original format value 518in RestrictedSchemeInfoBox shows that the component tracks 508 with atrack ID value of 24 and 25 are AVC encoded representations and thecomponent tracks 508 with a track ID value 516 of 27 and 28 are HEVCencoded alternative representations 522 of the component tracks 508 witha track ID value 516 of 24 and 25, respectively.

As shown in FIG. 5C, file 504 includes V3C contents that can havealternative representations 522. The component tracks 508 with track IDvalues 516 in the range between 1 and 4 comprises one V3C content andthe component tracks 508 with track ID value 516 in the range between 10and 18 comprises other V3C content. Two V3C atlas tracks 506 with a samealternative group value 512 indicates that the V3C contents included ineach of the V3C atlas tracks 506 are alternatives to each other. Incertain embodiments, the V3C content with V3C atlas track 506 with atrack ID value 516 of 1 is a version that does not use the V3C atlastile mechanism. The V3C content with V3C atlas track 506 with a track IDvalue 516 of 10 is a version that uses the V3C atlas tile mechanism. Forthe V3C video component tracks 508, the scheme type value 514 of thecomponent tracks 508 is ‘vvvc.’ The V3C video component tracks 508 aredirectly referenced by either V3C atlas track 506 or V3C atlas tiletracks 520. The track reference information in the V3C atlas tracks 506with a track ID value of 1 shows that the component tracks 508 withtrack ID values 516 of 2, 3 and 4 are the V3C video components tracks508 in the atlas track 506. The track reference information in the V3Catlas tile tracks 520 show that the component tracks 508 with a track IDvalue 516 of 13, 14 or 15 are the V3C video components tracks related toV3C atlas tile track 520 with a track ID value 516 of 11 and thecomponent tracks 508 with track ID values 516 of 16, 17 or 18 are theV3C video components tracks 508 related to V3C atlas tile track 520 witha track ID value 516 of 12. All the V3C video component tracks 508 arereferenced by a single V3C atlas track 506 or a single V3C atlas tiletrack 520.

For DASH 1MPD with video component alternatives, the value of @codecsparameter of the AdapationSet element for each video components shall beset to ‘resv.vvvc.XXXX’, where XXXX corresponds to the four-charactercode (4CC) of the video codec from the original format value 518 inRestrictedSchemeInfoBox of Sample Entry (e.g., ‘avcl’ or ‘hvcl’).

For DASH MPD, v3c:@atlas_id and VideoComponent@atlas_id, the parameterindicates the atlas id of the component track 508 carried by theadaptation set, which is present if multiple versions of the samevolumetric media are signalled in separate adaptation sets, i.e. V3Ccontent alternatives are presented, and video components associated toeach versions of the are also signalled in separate adaptation sets.

As shown in FIG. 5C, file 504 includes two V3C contents that havealternative representations 522. There are thirteen adaptation sets. Asadaptation set 524 does not have atlas tile encoding and adaptation set526 does has atlas tile, the adaptation sets 524, 526 are encoded asalternatives 528. However, adaptation sets 524 and 526 are defined asindividual adaptation sets. Two atlas tile tracks are also defined asindividual adaptation sets as they are alternatives each other. As thevideo component tracks 508 associated to the atlas track 506 withoutatlas tile encoding in adaptation set 524 are alternatives 528 to thevideo components tracks 508 associated to the atlas track 520 with atlastile encoding in adaptation set 526. All three component tracks 508 aredefined as individual adaptation sets. All video component tracks 508associated with atlas tile tracks 520 are defined as individualadaptation sets. Atlas tile preselection is used to indicate alternativerelationship of video components associated each atlas tile tracks 520.A same value of vID is assigned to both atlas tracks 506 as they arerepresenting same V3C content and alternative each other. The atlasIdparameter is provided to each adaptation sets for atlas tracks as theyare alternative relationship each other. As the video component tracksare part of different versions of V3C content, adaptation sets for thevideo component tracks also have an atlas Id parameter to reference anassociated atlas track so that relationship of video component tracksand atlas track can be known.

<?xml version=“1.0” encoding=“UTF-8”?> <MPD xmlns=“urn:mpeg:dash:schema:mpd:2011” xmlns:v3c=“urn:mpeg:mpegI:v3c:2020”  type=“static” mediaPresentationDuration=“PT10S”  minBufferTime=“PT1S” profiles=“urn:mpeg:dash:profile:isoff-on-demand:2011”> <Period>  <!--Main V3C AdaptationSet -->  <AdaptationSet id=“1” codecs=“v3c1”>   <!--V3C Descriptor -->   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” Id=“1” atlasId=“1” />  <Representation id=“1”>    ...   </Representation>  </AdaptationSet> <!-- Atlas Adaptation Set 1 -->  <AdaptationSet id=“2” codecs=“v3c1”>  <!-- V3C Descriptor -->   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” atlasId=“2” />  <Representation id=“2”>    ...   </Representation>  </AdaptationSet> <!-- Atlas Tile Adaptation Set 1 -->  <AdaptationSet id=“3”codecs=“v3t1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tiles=“1 2 3” />  <Representation dependencyId=“2”>    ...   </Representation> </AdaptationSet>  <!-- Atlas Tile Adaptation Set 2 -->  <AdaptationSetid=“4” codecs=“v3t1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” tiles=“4 5 6”/>  <Representation dependencyId=“2”>    ...   </Representation> </AdaptationSet>  <!-- Occupancy -->  <AdaptationSet id=“5”mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“occp” atlasId=“1” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“6” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“occp” atlasId=“2” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“7” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“occp” atlasId=“2” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet>  <!--Geometry -->  <AdaptationSet id=“8” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“geom” atlasId=“1” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“9” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“geom” atlasId=“2” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“10” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“geom” atlasId=“2” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet>  <!--Attribute -->  <AdaptationSet id=“11” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“attr” atlasId=“1” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“12” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“attr” atlasId=“2” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“13” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertychemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“attr” atlasId=“2” />   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet>  <!--Atlas Tile Preselections -->  <Preselection id=“1” tag=“1”preselectionComponents=“2 6 9 12” codecs=“v3t1”>   <!-V3C Descriptor -->  <EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1”/>  </Preselection>  <Preselection id=“2” tag=“2”preselectionComponents=“3 7 10 13” codecs=“v3t1”>   <!-V3C Descriptor-->   <EssentialProperty schemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c”Id=“1” />  </Preselection> </Period> </MPD>

For DASH MPD, v3c:@alt_id and VideoComponent@alt_id, the parameterindicating an alternative version of a V3C content carried by theadaptation set is present if multiple versions of same volumetric mediaare signalled in separate adaptation sets. For example when V3C contentalternatives are presented, video components associated to each versionsof the are also signalled in separate adaptation sets. Below is Table 1for elements and attributes for the V3C video component descriptor.

TABLE 1 Elements and attributes for the V3C video component descriptor.Elements and attributes Use Data type Description videoComponent@alt_idCM xs:integer Indicates the id of the alternative representation of aV3C Content the component represented by the Adaptation Set iscomprising. This attribute shall be present if multiple versions of samevolumetric media are signalled in separate Adaptation Sets and videocomponents associated to each versions of the are also signalled inseparate Adaptation Sets. Key: For attributes: M = Mandatory, O =Optional, OD = Optional with Default Value, CM = ConditionallyMandatory. For elements: <minOccurs> . . . <maxOccurs> (N = unbounded)Elements are bold; attributes are non-bold and preceded with an @.

Below is Table 2 for attributes for the V3C descriptor.

TABLE 2 Attributes for the V3C descriptor Attributes Use Data typeDescription v3c:@alt_id CM xs:integer Indicates the id of thealternative representation of a V3C Content the atlas represented by theAdaptation Set is comprsing. This attribute shall be present if multipleversions of same volumetric media are signalled in separate AdaptationSets Key: For attributes: M = Mandatory, O = Optional, OD = Optionalwith Default Value, CM = Conditionally Mandatory. For elements:<minOccurs> . . . <maxOccurs> (N = unbounded) Elements are bold;attributes are non-bold and preceded with an @.

This embodiment describes the case of file 504 with two V3C contents inalternative relationship as depicted in FIG. 5C. There are thirteenadaptation sets. There are two atlas adaptation sets. The same value ofvID is assigned to both atlas tracks 506 as they are representing thesame V3C content and are alternatives to each other. As the tile trackwithout atlas tile encoding and the tile track with atlas tile encodingare alternatives to each other, the tile tracks are defined asindividual adaptation sets and different values are assigned to the@alt_id attribute. Two atlas tile tracks are also defined as individualadaptation sets as they are alternatives each other. The Alternativerelationship of the atlas tile adaptation sets are indicated by havingsame value of @dependencyId. As the video component tracks associated tothe atlas track without atlas tile encoding are alternatives to thevideo components tracks associated to the atlas track with atlas tileencoding, video component tracks are defined as individual adaptationsets. As the video component tracks are part of different version of V3Ccontent, adaptation sets for the video component tracks also have alt_idparameter to reference atlas track associated with so that relationshipof video component tracks and atlas track can be known. All videocomponent tracks associated with atlas tile tracks are defined asindividual adaptation sets. For the representation atlas tile encodingis used, more than one video components with same @type value areassigned with same value of @alt_id. Preselection is provided todescribe the relationship between the atlas tile adaptation sets and thevideo component adaptation sets.

 <?xml version=“1.0” encoding=“UTF-8”?> <MPD xmlns=“urn:mpeg:dash:schema:mpd:2011” xmlns:v3c=“urn:mpeg:mpegI:v3c:2020”  type=“static” mediaPresentationDuration=“PT10S”  minBufferTime=“PT1S” profiles=“urn:mpeg:dash:profile:isoff-on-demand:2011”> <Period>  <!--Main V3C AdaptationSet -->  <AdaptationSet id=“1” codecs=“v3c1”>    <!--V3C Descriptor -->    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” alt_id=“1” />   <Representation id=“1”>     ...    </Representation> </AdaptationSet>   <!-- Atlas Adaptation Set 1 -->  <AdaptationSetid=“2” codecs=“v3c1”>    <!-- V3C Descriptor -->    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” alt_id =“2” />   <Representation id=“2”>     ...    </Representation> </AdaptationSet>   <!-- Atlas Tile Adaptation Set 1 -->  <AdaptationSetid=“3” codecs=“v3t1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tile_ids=“1 2 3” />   <Representation dependencyId=“2”>     ...    </Representation> </AdaptationSet>  <!-- Atlas Tile Adaptation Set 2 -->  <AdaptationSetid=“4” codecs=“v3t1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tile_ids=“4 5 6”/>   <Representation dependencyId=“2”>     ...    </Representation> </AdaptationSet>  <!-- Occupancy -->  <AdaptationSet id=“5”mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“occp” alt_id =“1” />   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>  <AdaptationSet id=“6” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“occp” alt_id =“2” tile_ids=“1 2 3” />   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>   <AdaptationSet id=“7” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“occp” alt_id =“2” tile_ids=“4 5 6”/>   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>  <!-- Geometry -->  <AdaptationSet id=“8”mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“geom” alt_id =“1” />   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>  <AdaptationSet id=“9” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“geom” alt_id =“2” tile_ids=“1 2 3” />   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>   <AdaptationSet id=“10” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“geom” alt_id =“2” tile_ids=“4 5 6”/>   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>  <!-- Attribute -->  <AdaptationSet id=“11”mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“attr” alt_id=“1” />   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>  <AdaptationSet id=“12” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“attr” alt_id =“2” tile_ids=“1 2 3” />   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>   <AdaptationSet id=“13” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>    <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>    <v3c:videoComponent type=“attr” alt_id =“2” tile_ids=“4 5 6”/>   </EssentialProperty>    <Representation>     ...    </Representation> </AdaptationSet>  <!-- Atlas Tile Preselections -->  <Preselectionid=“1” tag=“1” preselectionComponents=“2 6 9 12” codecs=“v3t1”>   <!-V3C Descriptor -->    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” />  </Preselection> <Preselection id=“2” tag=“2” preselectionComponents=“3 7 10 13”codecs=“v3t1”>    <!-V3C Descriptor -->    <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” />  </Preselection></Period> </MPD>

For DASH MPD, v3c:@vId, v3c:@atlas_id and VideoComponent@atlas_id, theparameter indicating an alternative version of a V3C content carried bythe adaptation set is present if multiple versions of same volumetricmedia are signalled in separate adaptation sets. For example, when V3Ccontent alternatives are presented, video components associated to eachversions of the are also signalled in separate adaptation sets. Theatlas tracks are signalled in separate adaptation sets. For the atlastile tracks not using atlas tile encoding, separate preselectionsincluding each of such atlas adaptation sets are defined to indicate thevideo component tracks associated with each atlas tracks. The atlas tiletracks using atlas tile encoding are not directly included in anypreselection but the preselection for each atlas tile tracks are definedto indicate the video component tracks associated with each atlas tiletracks. Through the dependency relationship between the atlas tile trackand the atlas track that comprises one of alternative representations ofa V3C content, it can be known that the atlas tile tracks are part ofone alternative representations of a V3C content indirectly.

This embodiment describes the case of two V3C contents in an alternativerelationship as depicted in the FIG. 5C. There are thirteen adaptationsets. There are two atlas adaptation sets. The same value of @vID and@atlas_id is assigned to both atlas tracks as they are representing thesame V3C content and are alternative to each other. As the tile trackwithout atlas tile encoding and the tile track with atlas tile encodingare alternatives each other, the tile tracks are defined as individualadaptation sets and the same values are assigned for the @atlas_idattribute. Two atlas tile tracks are also defined as individualadaptation sets as they are alternatives each other. Componentalternative relationship of the atlas tile adaptation sets are indicatedby having same value of @dependencyId. All video component tracksassociated with atlas tile tracks are defined as individual adaptationsets. Atlas tile preselection is used to indicate alternativerelationship of video components associated each atlas tile tracks. Twopreselections to indicate the video components for each atlas tiletracks are defined. As there are two atlas tracks with the same value of@vID and @atlas_id, the client can understand that there are twoalternative versions of an V3C content. As one of the preselectionsincludes one of the atlas adaptations set, the client can understandthat such preselection defines one representation of the V3C content. Astwo preselection includes the atlas tile adaptation sets and the atlastile adaptation sets are dependent on the atlas tile track, which is notpart of any preselection, then the client can understand that suchpreselections are part of another representation of the V3C contentusing the atlas tile track.

<?xml version=“1.0” encoding=“UTF-8”?> <MPD xmlns=“urn:mpeg:dash:schema:mpd:2011” xmlns:v3c=“urn:mpeg:mpegI:v3c:2020”  type=“static” mediaPresentationDuration=“PT10S”  minBufferTime=“PT1S” profiles=“urn:mpeg:dash:profile:isoff-on-demand:2011”> <Period>  <!--Main V3C AdaptationSet 1 -->  <AdaptationSet id=“1” codecs=“v3c1”>  <!-- V3C Descriptor -->   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” atlas_id=“1” />  <Representation id=“1”>    ...   </Representation>  </AdaptationSet><!-- Main V3C AdaptationSet 2 -->  <AdaptationSet id=“2” codecs=“v3c1”>  <!-- V3C Descriptor -->   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” atlas_id=“1”/>  <Representation id=“2”>    ...   </Representation>  </AdaptationSet><!-- Atlas Tile Adaptation Set 1 -->  <AdaptationSet id=“3”codecs=“v3t1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tile_ids=“1 2 3” />  <Representation dependencyId=“2”>    ...   </Representation> </AdaptationSet>  <!-- Atlas Tile Adaptation Set 2 -->  <AdaptationSetid=“4” codecs=“v3t1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” tile_ids=“4 5 6”/>  <Representation dependencyId=“2”>    ...   </Representation> </AdaptationSet>  <!-- Occupancy -->  <AdaptationSet id=“5”mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“occp” atlas_id=“1”/>   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“6” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“occp” atlas_id=“1” tile_ids=“1 2 3” />  </EssentialProperty>   <Representation>    ...   </Representation> </AdaptationSet>  <AdaptationSet id=“7” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“occp” atlas_id=“1” tile_ids=“4 5 6” />  </EssentialProperty>   <Representation>    ...   </Representation> </AdaptationSet>  <!-- Geometry -->  <AdaptationSet id=“8”mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“geom” atlas_id=“1”/>   </EssentialProperty>  <Representation>    ...   </Representation>  </AdaptationSet> <AdaptationSet id=“9” mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>  <EssentialProperty schemeIdUri=“urn:mpeg:dash:preselection:2016” />  <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“geom” atlas_id=“1” tile_ids=“1 2 3” />  </EssentialProperty>   <Representation>    ...   </Representation> </AdaptationSet>  <AdaptationSet id=“10” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“geom” atlas_id=“1” tile_ids=“4 5 6” />  </EssentialProperty>   <Representation>    ...   </Representation> </AdaptationSet>  <!-- Attribute -->  <AdaptationSet id=“11”mimeType=“video/mp4” codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“attr” atlas_id=“1” tile_ids=“4 5 6” />  </EssentialProperty>   <Representation>    ...   </Representation> </AdaptationSet>  <AdaptationSet id=“12” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“attr” atlas_id=“1” tile_ids=“1 2 3” />  </EssentialProperty>   <Representation>    ...   </Representation> </AdaptationSet>  <AdaptationSet id=“13” mimeType=“video/mp4”codecs=“resv.vvvc.hvc1”>   <EssentialPropertyschemeIdUri=“urn:mpeg:dash:preselection:2016” />   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:videoComponent”>   <v3c:videoComponent type=“attr” atlas_id=“1” tile_ids=“4 5 6” />  </EssentialProperty>   <Representation>    ...   </Representation> </AdaptationSet>  <!-- Atlas Tile Preselections -->  <Preselectionid=“1” tag=“1” preselectionComponents=“1 5 8 11” codecs=“v3c1”>   <!-V3CDescriptor -->   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” atlas_id=“1”/> </Preselection>  <Preselection id=“2” tag=“2” preselectionComponents=“36 9 12” codecs=“v3t1”>   <!-V3C Descriptor -->   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” atlas_id=“1”/> </Preselection>  <Preselection id=“3” tag=“3” preselectionComponents=“47 10 13” codecs=“v3t1”>   <!-V3C Descriptor -->   <EssentialPropertyschemeIdUri=“urn:mpeg:mpegI:v3c:2020:v3c” vId=“1” atlas_id=“1”/> </Preselection> </Period> </MPD>

Although FIGS. 5A through 5C illustrate files 500, 502, 504, variouschanges may be made to FIGS. 5A through 5C. For example, the sizes,shapes, and dimensions of the files 500, 502, 504 and each file'sindividual components can vary as needed or desired. Also, the numberand placement of various components of the files 500, 502, 504 can varyas needed or desired. In addition, the files 500, 502, 504 may be usedin any other suitable media processing process and is not limited to thespecific processes described above.

FIG. 6 illustrates an example method 600 for V3C video component trackalternatives according to this disclosure. For ease of explanation, themethod 600 of FIG. 6 is described as being performed using theelectronic device 300 of FIG. 3. However, the method 600 may be usedwith any other suitable system and any other suitable electronic device.

As shown in FIG. 6, the electronic device 300 can receive a plurality oftracks in a compressed bitstream at step 602. The plurality of trackscan be received from an internal storage, such as memory 360. Theplurality of tracks can also be received wirelessly through atransceiver, such as transceiver 310. The plurality of tracks can bereceived directly from an external device through an input, such asinput 350.

The electronic device 300 identifies an atlas track 506 corresponding toa PCC component at step 604. The atlas track 506 can be a first track ina file 500. The electronic device 300 can identify information in anatlas track that corresponds to the PCC component required for displayto the user.

The electronic device 300 identifies a set of first component tracksthat is referenced by the atlas track and at least one second componenttracks, where each of the at least one second component track is analternative version of a first component track of the set of firstcomponent tracks at step 606. The atlas track 506 can includeinformation that references one or more component tracks for PCCcontent. The at least one second component tracks are not directlyreferenced by the atlas track but have an indicator that matches one ofthe first component tracks. The indicator could be an alternate trackvalue. Multiple tracks (more than two) could include the same alternatetrack value. Each of the tracks with the alternate track value oralternatives for the PCC component. Other information included in thealternative component tracks can be used to indicate a suitable versionof the PCC component. For example, each of the alternative componenttracks could include an original format value. The PCC component coulduse the original format value to determine the suitable version of thePCC component based on the encoding type.

Alternative component tracks could be included under alternative atlastracks. Atlas tracks with a same alternate group value could indicatedifferent versions of the same object, encoded similarly or differently.In other words, a PCC component could have characteristics that aredifferent other than the encoding type. The alternate components couldbe different colors, orientations, etc.

The electronic device 300 determines which of the set of first componenttracks and the at least one second component track are appropriateversions of the PCC component at step 608. The electronic device 300 candetermine the appropriate version based on the characteristics of thedecoder, the requirements from the user, etc. The appropriate version isindicated through one or more of the values in the component track.

The electronic device 300 decodes the appropriate version of the PCCcomponent from among the set of first component tracks and the at leastone second component track at step 610. The electronic device 300decodes only the appropriate version of the PCC component, withoutprocessing any other of the alternative component tracks, alternativeatlas tracks, or alternative atlas tile tracks. The PCC component canthen be display appropriately to a user.

Although FIG. 6 illustrates one example of a method 600 for V3C videocomponent track alternatives, various changes may be made to FIG. 6. Forexample, while shown as a series of steps, various steps in FIG. 6 mayoverlap, occur in parallel, or occur any number of times.

Although the present disclosure has been described with exemplaryembodiments, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims. None of the description in this application should be read asimplying that any particular element, step, or function is an essentialelement that must be included in the claims scope. The scope of patentedsubject matter is defined by the claims.

What is claimed is:
 1. A decoding device for visual volumetricvideo-based coding (V3C) video component track alternatives, thedecoding device comprising: a communication interface configured toreceive a plurality of tracks in a compressed bitstream; and a processoroperably coupled to the communication interface, wherein the processoris configured to: identify an atlas track corresponding to a point cloudcompression (PCC) component; identify a set of first component tracksthat is referenced by the atlas track and at least one second componenttrack, each of the at least one second component track is an alternativeversion of a first component track of the set of first component tracks;determine which of the set of first component tracks and the at leastone second component track are appropriate versions of the PCCcomponent; and decode the appropriate version of the PCC component fromamong the set of first component tracks and the at least one secondcomponent track.
 2. The decoding device of claim 1, wherein, to identifythe at least one second component track, the processor is furtherconfigured to identify component tracks that have a same alternativegroup value.
 3. The decoding device of claim 1, wherein, to identify theat least one second component track, the processor is further configuredto identify component tracks that have a same value of an atlas ID. 4.The decoding device of claim 1, wherein: the alternative version is adifferently encoded representation of the PCC component, and the set offirst component tracks and the at least one second component trackrespectively have information about a codec used for the PCC component.5. The decoding device of claim 1, wherein only the set of firstcomponent tracks, among the set of first component tracks and the atleast one second component track, is directly referenced by the atlastrack.
 6. The decoding device of claim 1, wherein the compressedbitstream further includes an atlas tile track that is referenced by theatlas track, and only the set of first component tracks, among the setof first component tracks and the at least one second component track,is directly referenced by the atlas tile track.
 7. The decoding deviceof claim 1, wherein: the compressed bitstream includes a second atlastrack with a same alternative group value to the atlas track, and thesame alternative group value indicates that the second atlas trackrepresents an alternative version of the PCC component.
 8. A method forvisual volumetric video-based coding (V3c) video component trackalternatives, the method comprising: receiving a plurality of tracks ina compressed bitstream; and identifying an atlas track corresponding toa point cloud compression (PCC) component; identifying a set of firstcomponent tracks that is referenced by the atlas track and at least onesecond component track, each of the at least one second component trackis an alternative version of a first component track of the set of firstcomponent tracks; determining which of the set of first component tracksand the at least one second component track are appropriate versions ofthe PCC component; and decoding the appropriate version of the PCCcomponent from among the set of first component tracks and the at leastone second component track.
 9. The method of claim 8, wherein,identifying the at least one second component track, comprisesidentifying component tracks that have a same alternative group value.10. The method of claim 8, wherein identifying the at least one secondcomponent track comprises identifying component tracks that have a samevalue of an atlas ID.
 11. The method of claim 8, wherein: thealternative version is a differently encoded representation of the PCCcomponent, and the set of first component tracks and the at least onesecond component track respectively have information about a codec usedfor the PCC component.
 12. The method of claim 8, wherein only the setof first component tracks, among the set of first component tracks andthe at least one second component track, is directly referenced by theatlas track.
 13. The method of claim 8, wherein the compressed bitstreamfurther includes an atlas tile track that is referenced by the atlastrack, and only the set of first component tracks, among the set offirst component tracks and the at least one second component track, isdirectly referenced by the atlas tile track.
 14. The method of claim 8,wherein: the compressed bitstream includes a second atlas track with asame alternative group value to the atlas track, and the samealternative group value indicates that the second atlas track representsan alternative version of the PCC component.
 15. An encoding device forvisual volumetric video-based coding (V3c) video component trackalternatives, the encoding device comprising: a processor operablyconfigured to: encode an atlas track corresponding to a point cloudcompression (PCC) component; encode the PCC component in a firstcomponent track that references the atlas track; and encode analternative version of the PCC component from the first component trackin a second component track; and a communication interface operablycoupled to the processor, the communication interface configured totransmit a compressed bitstream including the atlas track, the firstcomponent track, and the second component track.
 16. The encoding deviceof claim 15, wherein the first component track and the second componenttrack are assigned with a same alternative group value.
 17. The encodingdevice of claim 15, wherein the first component track and the secondcomponent track are differently encoded representations of the PCCcomponent.
 18. The encoding device of claim 15, wherein only the firstcomponent track, of the first component track and the second componenttrack, is referenced by the atlas track.
 19. The encoding device ofclaim 15, wherein: the processor is further configured to: encode anatlas tile track that reference the atlas track, and only the firstcomponent track, of the first component track and the second componenttrack, directly references the atlas tile track.
 20. The encoding deviceof claim 15, wherein the processor is further configured to: encode asecond atlas track with a same alternative group value to the atlastrack, and encode a third component track that is referenced by thesecond atlas track and is an alternative to the first component trackand the second component track.